\section{Experiments} 

\begin{figure}
\centering
\includegraphics[width=0.8\textwidth ]{p12.png}
\caption{With CQ means that we use both attribute and class query component in the transition. Without CQ means that we use only attribute query component.}
\end{figure} 

\begin{figure}
\centering
\includegraphics[width=0.8\textwidth ]{p13.png}
\caption{Some results} 
\end{figure} 

Fig. 9 and Fig. 10, shows some preliminary results about the current implementation. Although not conclusive these results give a hint about the proposed technique. You can notice that there was a considerable reduction in the cardinality of the candidate sets in almost all cases when we use transition with both attribute query and class query (CQ), in the heuristic search. In the GEONAMES-GEONAMES case the use of a class query had not effect because the algorithm currently implemented could not detect a discriminative class query. It shows that there is a clear space for improvement in this elementary algorithm; however, even a simple algorithm can produce a huge reduction, in average. We did not evaluate the number of transition performed during the search because the current algorithm does not minimize QSP. In all cases there was no difference in the precision with or with class queries, and the algorithm found the candidate sets in half of the time when was used the class queries.
